Generally, an operator operates an operating lever of an excavating machine such as an excavator, and a work machine including a bucket is thereby driven to excavate the ground or the like as a work object. For example, Patent Literature 1 describes a technique of displaying a design difference and a bucket shape on a screen to be obtained in a work requiring accuracy by a backhoe, such as slope finishing. Patent Literature 2 describes a technique of a display system of a construction machine. In the system, a bucket symbol is displayed in accordance with a kind of the bucket actually included in the machine at present so that an excavating operation can be performed accurately.